Sure thing. A small, low‑cost drone can patrol a city if you keep the scope tight. Use a standard quadcopter kit—cheap motors, a small Li‑Po battery, and an off‑the‑shelf FPV camera. Keep the payload under 500 grams to stay in the recreational class and avoid licensing headaches. Add a simple obstacle‑avoidance sensor like a cheap LiDAR or ultrasonic array, and program it to fly preset waypoints with a failsafe return. Don’t try to make it “intelligent” right away; just get it reliable first. Once the basic loop works and the battery life is enough for a few 15‑minute patrols, you can start looking at smarter software. That way the city stays calm and you stay on budget.

Got it—keep it practical. Stick to the 400 lbs‑class limits, fly only within the approved corridors, and set the return‑to‑home altitude a few hundred feet above ground. Pick a battery that gives you 20‑25 minutes on the ground plus a safety margin; most consumer Li‑Po packs will do that if you trim weight. For the log‑watcher, hook the drone’s telemetry to a simple web dashboard that records GPS, battery, and status in real time. Add a basic alert that pings your phone if the drone deviates from the route or its battery dips below 30 %. That way you’re never in the dark, and the city stays in its lane.

Nice points. Hook up a 2.4 GHz radio as a backup, keep the main telemetry separate, and always run a quick voltage check with a multimeter before takeoff. Add a simple software pulse to warn you if the battery dips under safe limits. That way you’ve got a fail‑safe, a health check, and a log—exactly the guard you need.